Shipboard electrical treater

ABSTRACT

An electrical treater for resolving water-in-oil dispersions in a first enclosure positioned above a second enclosure in a shipboard mounting. The first enclosure contains dispersion inlet means, oil phase removing means and a coalescing section containing an electrical field to effect separation of the dispersion into continuous oil and water phases. An upright passageway transfers the water phase from the first enclosure to the second enclosure into a water accumulator with a body accumulated water being maintained below the upright passageway. Flow control means associated with the upright passageway provide for relatively unobstructed downward flow and restricted upward flow of the water phase between the first and second enclosures.

May 29., 1973 W T ET AL 3,736,245

I SHIPBOARD ELECTRICAL THEATER Filed Aug. 31, 1971 2 Sheets-Sheet 1 D WATSON ET AL 3,736,245

SHIPBOARD ELECTRICAL THEATER May 29, 1973 2 Sheets-Sheet 2 Filed Aug. 31, 1971 O O O Aid? United States Patent U.S. Cl. 204-302 Claims ABSTRACT OF THE DISCLOSURE An electrical treater for resolving water-in-oil dispersions in a first enclosure positioned above a second enclosure in a shipboard mounting. The first enclosure contains dispersion inlet means, oil phase removing means and a coalescing section containing an electrical field to effect separation of the dispersion into continuous oil and water phases. An upright passageway transfers the water phase from the first enclosure to the second enclosure into a water accumulator with a body of accumulated water being maintained below the upright passageway. Flow control means associated with the upright passageway provide for relatively unobstructed downward flow and restricted upward flow of the water phase between the first and second enclosures.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to the separation of oil-continuous dispersions; and in particular, it relates to an electrical treater for resolving Water-in-oil dispersions into oil and water phases in a shipboard environment.

(2) Description of the prior art The use of ocean-going supertankers in the last two decades has revolutionized maritime traffic in 'both the size, capacity, and speed of ocean vessels. For example, the tanker Manhattan was built in 1962. This vessel has a length of 892 feet, a beam of 132 feet with a load draft of approximately 50 feet. The vessel 1) displaces approximately 140,000 tons, (2) has a normal speed of nearly 18 knots and (3) is propelled by engines which generate nearly 40,000 steam horsepower applied through reduction gear turbines. Similar vessels built at the present time have substantially greater load capacities, physical sizes, and speeds so that propelling energy requirements are greatly increased. The majority of these supertankers carry full-capacity loads of crude oil from the Middle East to Japan, Europe, and the Western Hemisphere. The fuel for propelling these ships is principally heavy residual oils. However, the topped crude oil or residium available at loading points in the Middle East can be employed for ships fuel. For this purpose, the crude oil is first desalted according to conventional techniques, and then it is passed through a small refinery which extracts gasoline and kerosene distillates to leave a residium of the crude oil. Also, unprocessed but desalted heavy crude oil is quite satisfactory for combustion within steam boilers which generate the necessary steam for driving the steam turbines of the supertankers. The latest designs in propelling machinery for large ships have advanced technologically to directly-fueled gas turbine engines. For example, the jet engine employed on aircraft is of this turbine type. Similar gas turbine engines are employed in shipboard machinery where a desalted heavy residual oil provides directly the gaseous force for driving the turbines in the propelling machinery. The salt (NaCl) content of the fuel must be very low otherwise the gas turbine is severely injured and requires frequent expensive repairs.

Many crude oil supplies in several parts of the world, including the Middle East areas, contain little distillates that would justify operation of topping-type refineries. As a result, land-based desalting equipment cannot be economically justified by the topping refinery operations. However, land-based desalting equipment is absolutely required to process such low salt content crude oils into the liquid fuel required by the gas turbine propelling machinery.

The gas propelled turbine machinery for supertankers requires a fuel with extremely low salt contents. Salt contents in gas-turbine fuel above a value of approximately one pound per thousand barrels (55 gal. barrels) produce severe erosion of the turbines blades. Additionally, the water content of the crude oil fuel must be reduced to certain low values, e.g., .l.2% by volume. Amounts of water in excess of these small values lead to corrosion and other problems within gas turbine propelling machinery. Thus, the crude oil derived fuel must be low in both salt and water contents.

The crude oil is processed at the present time in shore facilities to a suitable quality for use as fuel on the supertankers. The vessels must contain segregated liquid storage for this fuel to prevent contamination by the untreated crude oil which forms the general cargo of the vessel. For example, a supertanker may carry a load of 200,000 barrels (or more) from the Middle East to the Eastern Seaboard of the United States. The tanker can consume approximately 80,000 barrels of fuel during this voyage. Other voyages require different amounts of fuel for the propelling machinery. Thus, the tanker must have ade quate clean storage, segregated from general cargo space to carry the fuel necessary for the propelling machinery. Reserved but unutilized non-general cargo storage space on the vessel drastically reduces the profit margin of the vessel. Thus, a reduction in segregated space for gasturbine fuel from the general cargo loading of the vessel is a much desired result.

The present invention is directed toward an electrical treater adapted to be mounted shipboard on ocean-going supertankers and the like. The treater is capable of resolving water-in-oil dispersions, of which crude oil is typical, into a desalted and dehydrated hydrocarbon fuel with an adequate purity for direct utilization in gas turbine powered ship machinery. With this shipboard treater, no shorebased pretreatment of crude oil forming the general cargo loading is required. The ship can be fueled directly from any of the crude oil in general cargo storage en route to its destination. Thus, the segregated space previously required for pre-processed fuel is avoided with a corresponding increase in general cargo capacity and increased economic reward from the vessels voyage.

The present electrical treater, unlike conventional electrical dehydrators or desalters, withstands the roll, pitch and yaw movements of an ocean-going vessel without short-circuiting or other problems in the electrical portions of the treater. For example, the latest supertankers have a roll between 8 to 32 seconds in period (which is approximately equivalent in displacement to plus or minus 30 degrees), a pitch of between 3 to 25 seconds in period (which corresponds in displacement to plus or minus 12 degrees), a vessel trim of plus or minus 7 degrees and a possible permanent list of plus or minus 15 degrees. Conventional electrical dehydrators or desalters would be soon destroyed by this oscillatory movement. Particularly, the accumulated body of water in these treaters would be accelerated to such velocities that water-masses would pass into the electrical sections of the treaters to shortcircuit the electrical field. Only the treater of the present invention is acceptable for shipboard use.

SUMMARY OF THE INVENTION In accordance with this invention, there is provided an electrical treater for resolving water-in-oil dispersion in a shipboard environment. The treater comprises first and second enclosures adapted to be mounted in a vertical spaced relationship. A coalescing section is provided in the first enclosure. The coalescing section includes means forming an electrical field to effect separation of the dispersion into continuous oil and Water phases. The first enclosure contains dispersion inlet means for passing the dispersion into the coalescing section and oil phase removal means for removing the oil phase therefrom. An upright passageway interconnects the first and second enclosures for transferring the water phase from the first enclosure to the second enclosure. The second enclosure provides a water accumulator with means for removing the water phase to maintain a body of accumulated water below the upright passageway. Flow control means are associated with the upright passageway to provide for relatively unobstructed downward flow of the water phase and to prevent any significant upward flow of the water phase between the first and second enclosures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross section of one embodiment of an electrical treater of the present invention;

FIG. 2 is a longitudinal vertical cross section taken along line 22 of the electrical treater shown in FIG. 1;

FIG. 3 is a vertical cross section of another electrical treater of this invention;

FIG. 4 is a vertical cross section of yet another electrical treater of this invention, and;

FIG. 5 is a schematic illustration of the displacement of the electrical treater of FIG. 4, when mounted shipboard, by wave action on the port side of an ocean vessel.

DESCRIPTION OF SPECIFIC EMBODIMENTS Referring now to FIG. 1 of the drawings, a preferred embodiment of an electrical treater 11 of the present invention is shown in a shipboard mounting. The treater 11 has an upper cylindrical vessel 12 superimposed above a lower cylindrical vessel 13. These vessels may be spherical. For handling large quantities of hydrocarbons, these vessels usually are horizontally-oriented, cylindrical-metal containers whose diameter and length depend upon the volume of oil to be processed. These vessels may have a length of 30 feet with the vessel 12 having a diameter of aproximately feet and the vessel 13 having a diameter of approximately 3 feet. The vessel 12 is mounted on shipboard by legs 14 secured to deck 16 which may be the main deck of the ship. The vessel 13 is mounted by legs 17 to the deck 16 in a similar fashion. Other shipboard mountings of these vessels may be employed, if desired.

An inlet 18 provides for introducing a water-in-oil dispersion (e.g., crude oil) through a distributing nozzle 19 for uniform fluid distribution in a horizontal plane. Fresh water (e.g., 2-10% by volume) may be intermixed with the incoming dispersion to assist in desalting the crude oil in the vessel 12. Reference may be taken to US. Pat. 2,527,690 for illustrations of such dispersion inlet arrangements. The dispersion passes from the nozzle 18 between a pair of foraminous horizontal electrodes 21 and 22. These electrodes may be a Welded grid of steel rods. The electrode 21 is suspended by vertical insulators 23 and interconnecting rods 24 and 26. Diagonal insulators 27 and rods 28 and 29 secure the upper electrode 21 from horizontal displacement. In a similar fashion, the electrode 22 is supported by vertical insulators 31 and rods 32 and 33. Horizontal displacement of the electrode 22 is prevented by diagonal insulators 34 and rods 36 and 37. In this manner the electrodes 21 and 22 within the vessel 12 remain operational during movements of their shipboard mounting.

The electrodes 21 and 22 can be energized from a transformer 38 having a primary 39 connecting to any suitable source of p er such as a steam dri e alternator. A secondary 41 with center tap 42 grounded to the sidewall of vessed 12, has energized conductors 43 and 44 which connect through bushings 46 and 47 to electrodes 21 and 22, respectively. Thus, the electrodes 21 and 22 are energized from the transformer 38 to an efiective potential to create the electrical field for resolving the dispersion within the vessel 12. Usually, the transformer 38 energizes the electrodes 21 and 22 (spaced apart 410 inches) at a potential of approximately 33,000 volts AC relative to one another and approximately 16,500 volts relative to the grounded sidewall of the vessel 12. A specific structure has been described for creating an electrical field within the vessel 12 capable of effecting separation of the dispersion into continuous oil and water phases but other arrangements of electrodes, entrance bushings, insulators, etc., may be employed, if desired.

The electrodes and nozzle within the vessel 12 provide a coalescing section in which the dispersion is resolved electrically into continuous oil and water phases. The oil phase collects in the upper portions of the vessel 12 and is substantially dehydrated and desalted. For example, the oil phase may have a 0.1% (volume) residual water content and a residual salt content of 1.0 pound of salt per 1000 barrels of oil phase. The oil phase is removed through an outlet 48 for direct utilization as fuel in the gas turbines forming the ships propulsion machinery. If desired, the outlet 38 may connect to a surge tank for dampening out pump pulsations, or for other reasons.

The droplets of water coalesced from the dispersion by the electric field, fall from the coalescing section toward the lower extremities of the vessel 12. In many instances, the oscillatory motion of the ship causes movements of the fluid within the vessel 12 to such extent as to remix the water droplets into the continuous oil phase. Where such motion-induced mixing is encountered, an egg-crate bafile assembly 49 may be installed intermediate the coalescing section and the lower extremity of the vessel 12. The baflle section 49 has right angle intersecting vertical walls which extend from sidewall to sidewall and substantially the length of the vessel 12. The bafiles carry a plurality of sidewall openings 51 and 52 to absorb en ergy from the sideway movement of fluids within the vessel 12.

The water droplets accumulate along the lower surfaces of the vessel 12. Then, the water droplets move, under the influence of gravity through an interconnecting upright passageway 53 into the vessel 13. For this result, the lower surface of the vessel 12 is shaped so that even in oscillatory movement of the shipboard mounting, the water droplets pass readily into the upper terminal 55 of the passageway '53 without accumulating into any significant mass within the vessel 12. Thus, the movement of the ship cannot accelerate a body of water in the vessel 12 of sufficient magnitude to 'be propelled into the vicinity of the electrodes 21 and 22 and short-circuit them to the adjacent grounded sidewall.

The passageway '53 is constructed of a short pipe carrying flanged connections 54 and 56 for interconnection between the vessel 12 and 13. The passageway 53 should have a sufiicient diameter for the unobstructed downward transfer of the coalesced water phase from the vessel 12 into the vessel 13. A single passageway 53 interconnecting the vessels may be sufficient for most shipboard purposes. As will be later described, several upright passageways can transfer the water phase from the vessel 12 into the vessel 13.

The vessel 13 provides a water accumulator for the treater 11. The water phase carried by the passageway 53 is accumulated within the vessel 13 and produces a body of water 57. The water body '57 is removed periodically or continuously, at a rate to maintain the upper water surface 58 below the lower terminal 59 of the passageway 53 by a water outlet 61 extending from the lower portion of the vessel 13. The removed Water c ries the salts removed from the crude oil and is discarded in a pollution free manner. The water outlet 61 has a motor valve 62 actuated between opened and closed position by a float 63 connected to a control unit 64. The unit 64 delivers an actuating signal through an interconnection (indicated by dashed line 66) to the valve 62. The float 63 senses the water surface 58 and the valve 62 is controlled to maintain the water surface 58 at a present horizon below the lower terminal 59 of the passageway 53.

Also, the passageway 53 carries flow control means to prevent any significant upward flow of the water phase between the vessels 12 and 13. Ocean ships undergo a rather severe oscillatory movement in roll and pitch. These ships can take a permanent list or trim position, as a result of these ship movements, water could be moved from the body of water 57 unwardly through the passageway 53 into the electrical field in the vessel 12. In small capacity treaters, the flow control means may be provided by correlating the length and internal dimensions of the passageway 53 to a predetermined maximum rotation of the first and second vessels from a vertical axis. For example, the vessels 12 and 13 may be subjected to no more than a 30 degree displacement from the vertical position shown in FIG. 1. With this displacement, the length of the passageway 53 must be sufiicient that the upper and lower terminals 55 and 59 of the passageway 53 (for a certain diameter) are not in a horizontal alignment which allows any significant port-ion of the body of water 57 to pass upwardly into the vessel 12. On large capacity treaters 11 employed on supertankers, the flow control means associated with the passageway 53 can incorporate other mechanisms.

The flow control means for the passageway 53 can include a check valve assembly 67. The check valve assembly 67, of any useable design, can be a float 68 arranged for closing movement upwardly against the valve 69 and downwardly opening movement against a lower cage support 71. The float 68 has a negative buoyancy in the oil phase contained in the vessel 13 above the body of water 57. However, the float 68 has a positive buoyancy in the water body 57 when the body of water 57 is displaced upwardly toward the upper terminal 55 of the passageway 53 and the float 68 is forced into fluid-tight engagement with the seat 69. This action seals the passageway 53 from any significant upward flow of the water phase into the vessel 12.

In some long term oscillatory movements of an oceangoing ship, the check valve 67 could be closed through a time equal to the period of roll or pitch of the shipboard mounting. Therefore, the passageway 53 preferably has a volumetric capacity to contain all of the water coalesced in the electric field throughout the longest-in-time period of either the roll or pitch. Generally, the maximum oscillatory period of an ocean-going ship is about 30 seconds. Thus, the passageway 53 should contain that amount of water coalesced from the dispersion in the vessel 12 through a time period of at least 30 seconds. The passageway 53 should have such a length to contain this amount of water even at a maximum permanent displacement in list or trim, which displacement usually will not exceed approximately 15 degrees. Thus, the passageway 53 and check valve assembly 67 can be constructed in the electrical treater 11 to function over all oscillatory motion and displacements of the shipboard mounting.

In many cases, length of the vessel 12 will be greater than 15 feet and several passageways, like passageways 53, are required for transferring water phase into the vessel 13.

As shown in FIG. 2, the passageway 53 should be placed mid-length of the vessel 12. Preferably, the float 63 is placed in a transverse plane aligned with the lower terminal 59 of the passageway 53'. Preferably, the upright passageways interconnecting the vessels 12 and 13 are placed in vertical alignment beneath the longitudinal axis of the vessel'12. In addition to the passageway 53 the vessels can carry at least second and third upright passageways 72 and 73. These passageways are provided with check valve assemblies 74 and 76 which may be constructed in the manner to check valve assembly 67.

In elongated lengths of the vessels 12 and 13, it is desirable to provide additional dispersion inlets 77 and 78 which supply dispersion to nozzles 79 and 81 and into the electrical field in the same manner as has been described for the inlet 18 and nozzle 19. The arrangement of insulators and support rods for the electrodes 21 and 22, along with the conductors for their energization has been omitted to simplify the View in FIG. 2.

The shipboard mounting of the vessel 12 and 13 may be displaced in thetir longitudinal axis from a horizontal plane by as much as 30 degrees. The body of water 57, after recovering from initial acceleration effects will as sume a position with the interface 58 horizontal. As a result, the check valve assembly 74 is closed by the upward movement of the body of water 57 to prevent the entry of water into the passageway 72. At this time, the passageways 53 and 73 are open to transfer water from the vessel 12 into the vessel 13'. Water will accumulate toward the volumetric capacity of the passageway 72 for the period of displacement. Once a body of water accumulates to fill the passageway 72, its hydrostatic head opens the float assembly 74 which action allows the accumulated water to pass from the passageway 72 into the body of water 57. At this time, the float 63 actuates the valve 62 to remove an equivalent amount of water through the outlet 61. The function of each check valve assembly is to prevent the upward movement of any significant amounts of water into the passageways during movement or displacement of the electrical treater 11 in the shipboard mounting. At all times, during oscillatory movement or at permanent list or trim conditions, water can flow downwardly in the unobstructed passageways into the body of water 57 in the vessel 13.

Any number of upright passageways may interconnect the vessels 12 and 13. It is preferable that suflicient passageways are present to intercept and remove, the coalesced water phase from several locations on the vessel 12. Prompt removal of the water phase irrespective of the maximum limits of roll, pitch and yaw, or trim and list, of the shipboard mounting prevents a buildup of the coalesced water into a mass capable of short-circuiting the electrodes 21 and 22 to the grounded sidewall of the vessel 12. For this purpose, one or more passageways are spaced longitudinally between the centrally disposed passageway 53 and the ends of the vessel 12.

Referring now to FIG. 3, there is shown another embodiment of the present electrical treater which is of a compact and integral vessel design. The electrical treater 81 is constructed with an upright cylindrical metalwalled vessel having curved top and bottom closures 82 and 83, respectively. A downwardly presented third curved closure 84 is carried in the vessel 81 intermediate the top and bottom closures 82 and 83. The closure 84 forms an upper enclosure containing electrodes 86 and 87 between which a dispersion is introduced from inlet 88 through the nozzle 89. The closures 82, 83 and 84 have an ellipsoidal configuration. The electrodes supporting insulators and energization components can be the same as in FIG. 1, but these elements are omitted for simplicity of description. The dispersion moves in the coalescing section from the nozzle 89 into the electrical field between the electrodes 86 and 87 to coalesce the water phase, as droplets, from the continuous oil phase which is removed through an outlet 91. The oil phase may be utilized directly as fuel in gas turbines for propelling a supertanker, or the like. The water droplets, by gravity effects, collect upon the closure 84 and readily pass into a centrally located upright passageway 92. Thepassageway 92 carries a check valve assembly 93 which can be constructed in the manner of check valve 67. A lower terminal 94 of the passageway 92 is maintained above the water surface 96 of a body of water 97 accumulating above the closure 83. For this purpose, water is removed from the vessel 81 through water outlet 98 in which flow is regulated by a control valve 99. A float 101 actuating a controller 102 senses the water surface 96 to operate the valve 99.

The passageway 92 permits the ready transfer of water downwardly from the coalescing section 85 into the body of water 97. However, the check valve assem' bly 93 prevents any significant movement of the body of water 97 upwardly into the coalesced section 85. The volume above the body of water 97 and below the conical closure 84 is filled with an oil phase which is substantially the same as the oil phase removed to the outlet 91. This oil phase volume provides a hydraulic cushion to dampen the surging of the body of water 97 during the oscillatory motion of the shipboard mounting. For example, a certain force is required by the body of water 97 to displace the oil from one side to the other of the vessel 81. This consumed force cushions the waters surging. 'In addition, the central location of the passageway 92 reduces to the minimum the amount of water which can actuate the check valve assembly 93. Therefore, the passageway 92 remains open to downward water flows substantially throughout the entire motion of the shipboard mounting. Thus, very little water will accumulate upon the closure 84 or within the passageway 92. As one result, the vertical dimension of the passageway 92, and its diameter, may be reduced rather substantially compared to the passageways of the treater 11.

The vessel 81 is mounted upon legs 103 to the deckplate 16. The vessel 81 is unitary in structure andfunction; and it can readily be installed upon an oceangoing ship and easily maintained during operation.

Referring now to FIG. 4, there is shown an embodiment of a treater 111 of the present invention useful in shipboard mountings with large displacements from the vertical axis. The electrical treater 111 includes an upper vessel '114 and a subtended lower vessel 116 supported by legs 112 and 117, respectively upon the deckplate 1 6. The vessel 114 has metal sidewall 143 with an upright conical shape mounted with its apex downward. A curved metal top 119, ellipsoidal in shape, encloses the sidewalls 143. The vessel 114 has acoalescing section I121 carrying energized electrodes 122 and 123. The supporting structures, power source, and energizing conductors etc., for these electrodes are omitted for sake of clarity but it is to be understood that the structures described in FIG. 1 may be utilized. A dispersion inlet 124 on the vessel 1-11 connects to a nozzle 126 for introducing dispersion into the electrical field between the electrodes 123 and 124.

The electrical field effectively separates the dispersion into a continuous oil phase removed through the outlet 127. From the outlet 127, the desalted-dehydrated oil phase may be subsequently utilized as the fuel for the gas turbine in the propelling machinery of the oceangoing ship. A horizontally disposed bafiie section 128 can be used to dampen horizontal flows immediately below the electrode assembly. The bafile section 128 is constructed with intersecting walls forming an egg-crate like structure. The walls carry a plurality of holes 129 and 131 for dampening the surging movement of the fluid within the vessel 114 during severe oscillatory movement of the shipboard mounting.

The water droplets coalesced from the dispersion by the electrical field in the coalescing section \121 fall to the lower extremity of the vessel 114 and enter the upper terminal 133 of an upright passageway 132. The passageway =132 has a lower terminal 134 which communicates with the interior of the vessel 116. The water, which passes downwardly through the passageay 132, accumulates within the vessel 116 as a body of water 136. The surface ,137 of the wate bo y 136 i controlled a 'relatively fixed horizon by controlled removal of water through a water outlet 138. The flow through the outlet 138 is controlled by a motor valve 139 actuated by float control assembly 141 with an interconnecting con trol connection indicated by dashed line 142. Thus, the water surface 137 is maintained constantly a substantial distance below the lower terminal 134 of the passageway 132.

The vertical dimension and diameter of the passageway =132 are arranged, with the electrical treater 111 inclined from the vertical to the maximum displacement to be encountered during shipboard mounting, that the water body.136 cannot pass upwardly through the now non-vertical passageway 132 into the vessel 114 and short-circuit the electrodes 122 and 123 to grounded metal sidewalls 143. If desired, the lower terminal 134 of the passageway 132 may be provided with a check valve assembly such as described in the earlier embodiments.

The conical sidewalls 143 have a selected sloping structure so that the electrical treater 111 is operative even in severe displacements from a vertical axis during shipboard mounting.

Referring momentarily to FIG. 5, there is a schematic illustration of an ocean-going vessel 114 at a roll to an angle of approximately 30 degrees and indicated by the numeral 146. The vessel 144 is displaced by a wave 147 which has impinged upon the port side of the vessel 144. The treater 111, in schematic illustration, has the sidewall 143 on the right side displaced from the orientation shown in FIG. 4 toward the horizontal shown by a line 148. In accordance with this embodiment of the present invention, the slope of the sidewall 143 is selected that the sidewall 143 is above and always maintains at least an acute angle relative to the horizontal line (148 during maximum roll displacement along the longitudinal axis of the vessel 144. As a result, the falling water droplets from the coalescing section 1211 impinge upon the sidewall 143 and then move downwardly into the upper terminal 133 of the passageway 132 for unobstructed passage into the vessel 116.

Preferably, the vessel 111 is mounted at or at least above the metacenter 149 of the vessel 144. This mounting is the most stable shipboard position for the electricaltreater 111. As the treater 111 is mounted further from the metacenter 149 of the ship 144, the greater is the influence of roll and pitch of the vessel upon the fluid contained in the electrical treater, and the greater will be the acceleration effects upon the water body 136.

Returning now to FIG. 4, the electrical treater 111 with sloping sidewalls 143 will function during all possible displacements in roll or pitch, or any permanent list or trim configuration, that the ship upon which it is mounted can tolerate without destruction. Any displacement which would prevent electrical treater 111 from operating properly would destroy the ocean-going ship upon which it is mounted.

The electrical treaters of the present invention provide for the electrical resolution of various water-in-oil dispersions, such as untreated crude oil carried as general cargo of a supertanker. This crude oil is treated in the present electrical treaters to provide a clean and adequate fuel for operation of gas turbines in the propelling machinery of ocean-going ships. In addition, the electric treaters of the present invention reduce the amount of segregated fuel storage space and avoid intermittent operation caused by the ships motion in roll, pitch or yaw about its axis, or changes in trim or pitch.

Various modifications and alterations in the electrical treater of the present invention will be apparent to those skilled in the art from the foregoing description, which variations do not depart from the spirit of the invention. For this reason, these variations are desired to be included within the scope of the appended claims. The appended claims define the present invention; the foregoing description is to be employed for setting forth the present embodiments as illustrative in nature.

What is claimed is:

1. An electrical treater for resolving water-in-oil dispersions in a shipboard environment comprising:

(a) first and second enclosures mounted in a vertical spaced relationship, said first enclosure being superimposed above said second enclosure;

(b) a coalescing section in said first enclosure, said coalescing section including means forming an electrical field to effect separation of said dispersion into continuous oil and water phases, and dispersion inlet means for introducing said dispersion into said first enclosure for upward movement into said electrical field and oil phase removal means carried on said first enclosure for withdrawing the continuous oil phase from above said electrical field in the upper portion of said first enclosure;

(c) an upright passageway interconnecting said first and second enclosures for transferring the water phase from the lower extremity of said first enclosure to said second enclosure immediately upon the Water phase being coalesced from said dispersion falling to the lower portion of said first enclosure;

(d) said second enclosure providing a water accumulator with means for removing the water phase to maintain a body of accumulated water below said upright passageway; and

(e) flow control means associated with said upright passageway to provide for relatively unobstructed downward flow of the water phase and to prevent any significant upward flow of the water phase between said first and second enclosures to the extent that no body of water resides in said first enclosure below said electrical field during displacements of said first and second enclosures from an upright position in the shipboard enviroment.

2. The treater of claim 1 wherein said flow control means include an upwardly closing check valve adjacent the lower extremity of said passageway, and said check valve selectively closing upon any significant upward flow of the water phase between said first and second enclosures.

3. The treater of claim 1 wherein said flow control means includes a certain vertical dimension of said passageway, and said vertical dimension providing a spacing between upper and lower terminals of said passageway such that a predetermined maximum rotation from a vertical axis of said first and second enclosures will not place said upper and lower terminals of said passageway into a horizontal alignment whereby any significant portion of the body of accumulated water can flow from said second enclosure into said first enclosure.

4. The treater of claim 2 wherein level control means are carried on said second enclosure to maintain the body of accumulated water below said check valve with said first and second enclosures standing upright.

5. The treater of claim 1 wherein said first enclosure is formed of an upright vessel having circular cross-sections in several horizontal planes.

6. The treater of claim 1 wherein said first enclosure is formed of an upright conical-shaped vessel mounted apex downwardly above said second enclosure.

7. The treater of claim 6 wherein said vessel has a conical-shaped sidewall extending from the region of said electrical field downwardly to the upper terminal of said passageway, and said conical-shaped sidewall having a slope such that upon maximum displacement from the vertical with said vessel mounted shipboard, said sidewall always maintains at least an acute angle relative to the horizontal.

8. The treater of claim 1 wherein said first and second enclosures are provided by an upright cylindrical vessel having top and bottom outwardly cured closures, and a downwardly presented third curved closure intermediate said top and bottom closures to segregate said vessel into 10 said first and second enclosures, said third curved closure connected at its lower extremity to the upper terminal of said passageway carrying said flow control means.

9. The treater of claim 8 wherein said flow control means are a check valve.

10. The treater'of claim 1 wherein a horizontally-extending bafile section is positioned in said first enclosure at a horizontal between the region of said electrical field and the upper terminal of said passageway, and said baffle section limiting horizontal displacement of water droplets coalesced from the dispersion by said electrical field.

11. An electrical treater for resolving water-in-oil dispersions in a shipboard environment comprising:

(a) a horizontally-oriented cylindrical first vessel carrying dispersion inlet means, oil phase removal means and a coalescing section including means forming an electrical field to effect separation of said dispersion into continuous oil and water phases, and said dispersion inlet means introducing said dispersion into said first vessel for upward movement into said electrical field and said oil removal means withdrawing the continuous oil phase from above said electrical field in the upper portion of said first vessel;

(b) a horizontally-oriented cylindrical second vessel disposed in vertical spaced relationship below said first vessel;

(c) at least one upright passageway interconnecting said first and second vessels for transferring the water phase from the lower extremity of said first vessel to said second vessel immediately upon the water phase being coalesced from said dispersion falling to the lower portion of said first vessel;

(d) said second vessel providing a water accumulator with means for removing the water phase to maintain a body of accumulated water below said upright passageway; and

(e) flow control means associated with said upright passageway to provide for relatively unobstructed downward flow of said water phase and to prevent any significant upward flow of the water phase between said first and second vessels to the extent that no body of water resides in said first enclosure below said electrical field during displacements of said first and second vessels from an upright position in the shipboard environment.

12. The treater of claim 11 wherein said flow control means include an upwardly closing check valve at the lower extremity of said passageway, and said check valve selectively closing upon any significant upward flow of the water phase between said first and second vessels.

13. The treater of claim 12 wherein said level control means are carried on said second vessel to maintain the body of accumulated water below said check valve with said first vessel disposed with its longitudinal axis in the horizontal.

14. The treater of claim 11 wherein a first upright pas sageway interconnects said first and second vessels 'at a location along the longitudinal axis and in the center of said first vessel, and at least second and third upright passageways interconnect said first and second vessels at loca tions midlength of the longitudinal axis between said first upright passageway and each end of said first vessel respectively and each of said upright passageways, at their lower extremity, carry an upwardly closing check valve to prevent any significant flow of the water phase between said first and second vessels.

15. The treater of claim 11 wherein said first vessel carries a horizontally extending batfle section in a horizon between the region of said electrical field and the upper terminals of said upright passageways, and said baffie section limiting horizon displacement of water droplets coalesced from the dispersion by said electrical field.

16. The treater of claim 12 wherein said level control means are carried on said second vessel below said first upright passageway to maintain the body of accumulated water below said check valve with the longitudinal axis of said first vessel disposed in the horizontal.

17. The treater of claim 14 wherein said upright passageways have a volumetric capacity to receive substantially all of the coalesced water phase from said first vessel intermediate the maximum oscillatory period with said vessels mounted shipboard.

18. The treater of claim 17 wherein the volumetric capacity of said upright passageways is adequate to receive the coalesced water phase accumulated when the oscillatory period of the shipboard mounting is about 30 seconds.

19. The treater of claim 14 wherein said upright passageways are spaced along the length of the longitudinal axis of said first vessel whereby the coalesced water phase is removed to said second vessel through at least one of said passageways when said first vessel is non-horizontally displaced by a shipboard mounting to the maximum limits of roll, pitch and yaw without .the coalesced Water phase short-circuiting said electrical field to electrical grounds.

12 20. The treater of claim 19 wherein the maximum limits in the shipboard mounting of roll and pitch are about 30 degrees, and about 12 degrees, respectively.

References Cited UNITED STATES PATENTS JOHN H. MACK, Primary Examiner T. TUFARIELLO, Assistant Examiner US. Cl. X.R. 204-306 

